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1.
J Cell Biol ; 222(9)2023 09 04.
Article in English | MEDLINE | ID: mdl-37358475

ABSTRACT

Cell biologists typically focus on conserved regions of a protein, overlooking innovations that can shape its function over evolutionary time. Computational analyses can reveal potential innovations by detecting statistical signatures of positive selection that lead to rapid accumulation of beneficial mutations. However, these approaches are not easily accessible to non-specialists, limiting their use in cell biology. Here, we present an automated computational pipeline FREEDA that provides a simple graphical user interface requiring only a gene name; integrates widely used molecular evolution tools to detect positive selection in rodents, primates, carnivores, birds, and flies; and maps results onto protein structures predicted by AlphaFold. Applying FREEDA to >100 centromere proteins, we find statistical evidence of positive selection within loops and turns of ancient domains, suggesting innovation of essential functions. As a proof-of-principle experiment, we show innovation in centromere binding of mouse CENP-O. Overall, we provide an accessible computational tool to guide cell biology research and apply it to experimentally demonstrate functional innovation.


Subject(s)
Centromere , Computational Biology , Computer Simulation , Evolution, Molecular , Proteins , Animals , Mice , Rats , Birds , Cell Biology , Chromosomal Proteins, Non-Histone/chemistry , Chromosomal Proteins, Non-Histone/genetics , Chromosomal Proteins, Non-Histone/metabolism , Computational Biology/methods , Drosophila , Primates , Protein Domains/genetics , Proteins/chemistry , Proteins/genetics , Proteins/metabolism
2.
bioRxiv ; 2023 Feb 28.
Article in English | MEDLINE | ID: mdl-36909479

ABSTRACT

Cell biologists typically focus on conserved regions of a protein, overlooking innovations that can shape its function over evolutionary time. Computational analyses can reveal potential innovations by detecting statistical signatures of positive selection that leads to rapid accumulation of beneficial mutations. However, these approaches are not easily accessible to non-specialists, limiting their use in cell biology. Here, we present an automated computational pipeline FREEDA (Finder of Rapidly Evolving Exons in De novo Assemblies) that provides a simple graphical user interface requiring only a gene name, integrates widely used molecular evolution tools to detect positive selection, and maps results onto protein structures predicted by AlphaFold. Applying FREEDA to >100 mouse centromere proteins, we find evidence of positive selection in intrinsically disordered regions of ancient domains, suggesting innovation of essential functions. As a proof-of-principle experiment, we show innovation in centromere binding of CENP-O. Overall, we provide an accessible computational tool to guide cell biology research and apply it to experimentally demonstrate functional innovation.

3.
Clin Pediatr (Phila) ; 62(4): 301-308, 2023 05.
Article in English | MEDLINE | ID: mdl-36171719

ABSTRACT

This pilot study assessed the feasibility and potential effectiveness of a single-session workshop in modifying parental beliefs/knowledge about attention-deficit/hyperactivity disorder (ADHD) in children and impact on treatment acceptance/utilization. Concerns raised by school professionals about lack of treatment follow-through after ADHD diagnosis and parental misinformation about medication usage catalyzed this project. A single-group pre-post quasi-experimental design was used. Sixty-eight parents completed ADHD knowledge/belief scales and stress inventories, and pre-ADHD and post-ADHD information workshop. Follow-up calls were made after the workshop to assess treatment utilization. Parents/caregivers experienced significant knowledge and belief changes regarding medication efficacy, willingness to accept physician treatment recommendations, and rejection of non-empirically based treatments. Follow-up data showed that 41% of contacted participants met with physicians to discuss medication utilization and behavioral treatments. Brief, one-session psycho-educational workshops were feasible and impacted parental beliefs and behaviors regarding scientifically supported interventions for ADHD.


Subject(s)
Attention Deficit Disorder with Hyperactivity , Child , Humans , Attention Deficit Disorder with Hyperactivity/therapy , Attention Deficit Disorder with Hyperactivity/diagnosis , Pilot Projects , Parenting , Parents , Schools
4.
Cell ; 184(19): 4904-4918.e11, 2021 09 16.
Article in English | MEDLINE | ID: mdl-34433012

ABSTRACT

Selfish centromere DNA sequences bias their transmission to the egg in female meiosis. Evolutionary theory suggests that centromere proteins evolve to suppress costs of this "centromere drive." In hybrid mouse models with genetically different maternal and paternal centromeres, selfish centromere DNA exploits a kinetochore pathway to recruit microtubule-destabilizing proteins that act as drive effectors. We show that such functional differences are suppressed by a parallel pathway for effector recruitment by heterochromatin, which is similar between centromeres in this system. Disrupting the kinetochore pathway with a divergent allele of CENP-C reduces functional differences between centromeres, whereas disrupting heterochromatin by CENP-B deletion amplifies the differences. Molecular evolution analyses using Murinae genomes identify adaptive evolution in proteins in both pathways. We propose that centromere proteins have recurrently evolved to minimize the kinetochore pathway, which is exploited by selfish DNA, relative to the heterochromatin pathway that equalizes centromeres, while maintaining essential functions.


Subject(s)
Centromere Protein B/metabolism , Centromere/metabolism , Chromosomal Proteins, Non-Histone/metabolism , Alleles , Amino Acid Sequence , Animals , Biological Evolution , CRISPR-Cas Systems/genetics , Centromere Protein A/metabolism , Chromosomal Proteins, Non-Histone/chemistry , Chromosomes, Mammalian/metabolism , Female , Heterochromatin/metabolism , Kinetochores/metabolism , Male , Mice, Inbred C57BL , Models, Biological , Oocytes/metabolism , Protein Domains
5.
Clin Genet ; 84(6): 546-51, 2013 Dec.
Article in English | MEDLINE | ID: mdl-23373759

ABSTRACT

FMR1 premutation carriers are common in the general population (1/130-260 females and 1/250-810 males) and can be affected by fragile X-associated tremor ataxia syndrome, fragile X-associated primary ovarian insufficiency, anxiety, depression, hypertension, sleep apnea, fibromyalgia, and hypothyroidism. Here we report the results of a pilot study to assess the prevalence and risk of migraine in FMR1 premutation carriers. Three hundred fifteen carriers (203 females; 112 males) and 154 controls (83 females; 71 males) were seen sequentially as part of a family study. A standardized medical history, physical examination and confirmation of diagnosis of migraine headaches were performed by a physician. The prevalence of migraine was 54.2% in female carriers (mean age/SD: 49.60/13.73) and 26.79% in male carriers (mean age/SD: 59.94/14.27). This prevalence was higher compared to female (25.3%; mean age/SD: 47.60/15.21; p = 0.0001) and male controls (15.5%; mean age/SD; 53.88/13.31; p = 0.0406) who underwent the same protocol and were confirmed to be negative for the FMR1 mutation by DNA testing. We hypothesize that the increased prevalence of migraine headaches in FMR1 premutation carriers is likely related to the mitochondrial abnormalities that have recently been reported. Screening for migraine should be considered when evaluating FMR1 premutation carriers in the future.


Subject(s)
Fragile X Mental Retardation Protein/genetics , Heterozygote , Migraine Disorders/epidemiology , Migraine Disorders/genetics , Adult , Aged , Case-Control Studies , Female , Humans , Male , Middle Aged , Migraine Disorders/diagnosis , Prevalence , Risk , Trinucleotide Repeat Expansion
6.
Infection ; 41(2): 329-37, 2013 Apr.
Article in English | MEDLINE | ID: mdl-22886774

ABSTRACT

BACKGROUND: The nomenclature of Streptococcus bovis has changed. The study aims were to examine and compare the clinical characteristics and outcomes of infections based on the new taxonomy and the genetic relatedness of strains. METHODS: Bacteremic cases from 2004 to 2010 at Assaf Harofeh Medical Center were reviewed. VITEK 2 later confirmed with polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) was used for subspecies identification. VITEK 2 later confirmed with Etests was used for minimal inhibitory concentration (MIC) testing. Repetitive extragenic palindromic polymerase chain reaction (rep-PCR) was used to determine the genetic relatedness of strains. RESULTS: Twenty-four bacteremia cases were included. The median age of patients was 81 years (range 1 day to 91 years), two were neonates, three were pregnant, and 18 were elderly (≥ 65 years of age). The Charlson's combined conditional age-related score was 8.2 ± 2.9, and 11 (58 %) patients were immunosuppressed. There were 13 patients who had S. gallolyticus subsp. pasteurianus, six had S. gallolyticus subsp. gallolyticus, four had S. infantarius subsp. coli, and one had S. infantarius subsp. infantarius. Ten of 19 non-pregnant adult patients had colon adenoma or carcinoma, three had acute biliary disease, and five had endocarditis. Two patients died in the hospital. rep-PCR revealed polyclonality. There were no significant associations between subspecies or genotypes and the various clinical characteristics or outcomes. CONCLUSION: S. bovis bacteremia is a serious disease that affects elderly immunosuppressed individuals. Infection is strongly associated with colon pathology and endocarditis, regardless of the new taxonomy or clone complex. The identification of S. bovis is of paramount importance, and microbiology laboratories should differentiate its processing from that of other S. viridans.


Subject(s)
Colonic Neoplasms/microbiology , Endocarditis, Bacterial/microbiology , Streptococcus bovis/classification , Adolescent , Adult , Aged , Aged, 80 and over , Anti-Bacterial Agents/pharmacology , Bacteremia/microbiology , Bacterial Typing Techniques , Biliary Tract Diseases/epidemiology , Biliary Tract Diseases/microbiology , Biliary Tract Diseases/pathology , Child , Child, Preschool , Colonic Neoplasms/epidemiology , Colonic Neoplasms/pathology , Comorbidity , Endocarditis, Bacterial/epidemiology , Endocarditis, Bacterial/pathology , Female , Humans , Immunocompromised Host , Infant , Infant, Newborn , Israel , Male , Microbial Sensitivity Tests , Middle Aged , Polymerase Chain Reaction , Polymorphism, Restriction Fragment Length , Pregnancy , Prospective Studies , Streptococcus bovis/drug effects , Streptococcus bovis/genetics , Young Adult
7.
BJOG ; 118(5): 533-49, 2011 Apr.
Article in English | MEDLINE | ID: mdl-21251190

ABSTRACT

Vaginal microbiome studies provide information that may change the way we define vaginal flora. Normal flora appears dominated by one or two species of Lactobacillus. Significant numbers of healthy women lack appreciable numbers of vaginal lactobacilli. Bacterial vaginosis (BV) is not a single entity, but instead consists of different bacterial communities or profiles of greater microbial diversity than is evident from cultivation-dependent studies. BV should be considered a syndrome of variable composition that results in different symptoms, phenotypical outcomes, and responses to different antibiotic regimens. This information may help to elucidate the link between BV and infection-related adverse outcomes of pregnancy.


Subject(s)
Bacteria/isolation & purification , Metagenome/genetics , Pregnancy Complications, Infectious/microbiology , Vagina/microbiology , Vaginosis, Bacterial/microbiology , Bacteria/genetics , Bacteriological Techniques , Female , Humans , Pregnancy , Pregnancy Complications, Infectious/diagnosis , Prenatal Diagnosis/methods , Vaginosis, Bacterial/diagnosis
8.
Clin Med Insights Pathol ; 3: 13-7, 2010 May 19.
Article in English | MEDLINE | ID: mdl-21151550

ABSTRACT

Thrombotic microangiopathies are disorders resulting from platelet thromboses forming in the microvasculature with resultant schistocyte forms. Hemolytic uremic syndrome (HUS) is a microangiopathic hemolytic anemia often complicated by acute renal failure in children. HUS is typically caused by bacterial infection, most commonly enterohemorrhagic Escherichia coli. Neuraminidase-producing organisms, such as Streptococcus pneumoniae have also been reported as potential etiologies. The pathogenesis in these cases involves cleavage of sialic acid residues from the surfaces of erythrocytes, platelets, and glomerular capillary endothelial cells, exposing the Thomsen-Friedenreich antigen, a process known as T-activation. We describe a 2-year-old girl who presented with pneumococcal pneumonia and sepsis ultimately resulting in a thrombotic microangiopathy with acute renal failure, most consistent with HUS. The patient's direct antiglobulin test was positive. Polyagglutination was observed with human adult serum, but not with umbilical cord serum. Her red blood cells (RBCs) were reactive against peanut and soybean lectins, but not Salvia sclarea or Salvia horminum lectins. These findings are consistent with T-activation. Clinicians should be cognizant of the possibility of T-activation with resultant HUS in patients infected with neuraminidase-producing bacteria. Such patients may be difficult to identify using monoclonal typing antisera, as these typically do not have anti-T antibodies. Whether such patients are at risk for transfusion-associated hemolysis is debatable.

9.
Neurotherapeutics ; 7(3): 307-19, 2010 Jul.
Article in English | MEDLINE | ID: mdl-20643384

ABSTRACT

This review focuses on helping clinicians identify resources and develop strategies they may use to effectively negotiate safe and effective use of complementary and alternative medicine (CAM) treatments with families of children with autism spectrum disorders (ASD), as well as other neurodevelopmental disorders. Since new types of CAM continue to be introduced into the autism community, emphasis is placed on providing clinicians with tools to help families negotiate the myriad of available treatments and make decisions based on current safety and efficacy data, while remaining mindful of the reasons families may be considering these treatments. We familiarize readers with high-quality, evidence-based resources that providers and families may use to ascertain current information about specific types of CAM, verify the content of biologically-based treatments, identify ongoing CAM research and obtain toolkits designed to help healthcare providers raise the topic of CAM usage and facilitate disclosure and discussion of CAM use with patients and their families.


Subject(s)
Autistic Disorder/therapy , Complementary Therapies/methods , Complementary Therapies/trends , Evidence-Based Medicine , Family Health , Humans
10.
Am J Med Genet A ; 149A(11): 2501-6, 2009 Nov.
Article in English | MEDLINE | ID: mdl-19842197

ABSTRACT

Women with fragile X mental retardation (FMR1) gene premutations (55-200 CGG repeats) were until recently believed to be unaffected. It is now known that up to 8% of older female FMR1 premutation carriers develop fragile X-associated tremor/ataxia syndrome (FXTAS). Female carriers may also develop primary ovarian insufficiency, thyroid disease, hypertension, seizures, peripheral neuropathy, and fibromyalgia. We present a 60-year-old woman with FMR1 premutation who had depression, anxiety, and conversion disorder with seizures. The FMR1 premutation with its associated mRNA toxicity is postulated as an underlying neurobiological mechanism of conversion symptoms, through functional and structural neural dysconnectivity.


Subject(s)
Conversion Disorder/genetics , Fragile X Mental Retardation Protein/genetics , Mutation/genetics , Adult , Female , Humans , Magnetic Resonance Imaging , Middle Aged
11.
Curr Infect Dis Rep ; 9(6): 485-500, 2007 Nov.
Article in English | MEDLINE | ID: mdl-17999885

ABSTRACT

Bacterial vaginosis (BV) is an enigmatic polymicrobial disease, and its evolution and pathobiology will not be solved by traditional culture-based methods. Characterization of the vaginal microbiota by polymerase chain reaction-based methods holds great promise. Molecular studies have identified species not detected by culture, but they also have missed some species identified by culture. These studies allow classification of both normal and BV patients based on distinct microbiologic profiles, which may prove important in accessing risk of BV, response to treatment, and risk of complications. More studies using new generations of primers and standardized methods are needed, and data must be analyzed after grouping patients according to microbiologic profiles.

12.
Drugs ; 61(1): 1-7, 2001.
Article in English | MEDLINE | ID: mdl-11217866

ABSTRACT

Methicillin-resistant Staphylococcus aureus is a pathogen that is associated with serious infections that pose a significant risk of morbidity and mortality because of their multidrug resistant nature. Until recently, therapeutic options were limited to vancomycin, making the use of this drug widespread. Unfortunately, the continued application of this drug has led to the emergence of glycopeptide intermediate susceptible S. aureus (GISA). By definition, these organisms demonstrated a vancomycin minimum inhibitory concentration (MIC) of >4 mg/L and <32 mg/L. However, although the mechanism of resistance is not fully elucidated at this time, GISA strains have demonstrated thickened or aggregated cell walls, an increase in penicillin binding proteins and greater autolytic activity. At present, the overall number of reported cases of GISA is relatively low. In most cases, thus far, prolonged courses of vancomycin were reported. A few cases reported monitoring serum vancomycin concentrations but because of limited information, no association with outcome can be made. Whether these GISA strains will become more widespread or evolve into fully glycopeptide resistant strains is unknown at this time. Although there are a number of new agents that possess activity against these pathogens, there is no consensus regarding specific recommendations for treatment. Strict infection control practices, routine screening for resistance and controlled use of antibacterial agents, especially vancomycin, are critical steps in preventing the further development of resistance among staphylococci.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Methicillin Resistance/physiology , Staphylococcal Infections/drug therapy , Staphylococcus aureus/drug effects , Vancomycin/therapeutic use , Humans , Staphylococcal Infections/microbiology , Staphylococcus aureus/physiology
13.
Antimicrob Agents Chemother ; 45(2): 454-9, 2001 Feb.
Article in English | MEDLINE | ID: mdl-11158740

ABSTRACT

Daptomycin is an investigational lipopeptide antibiotic active against gram-positive organisms. The mechanism of action is unique, resulting in interference with cell membrane transport. The bactericidal activity of daptomycin was evaluated against glycopeptide-intermediate susceptible Staphylococcus aureus (GISA), vancomycin-resistant Enterococcus faecium (VREF), and methicillin-resistant S. aureus (MRSA) in an in vitro infection model with simulated endocardial vegetations. Simulated regimens of daptomycin at 6 mg/kg/day (D6) and 10 mg/kg/day (D10) were utilized. MICs and MBCs for daptomycin were determined in the absence and in the presence of albumin with the following results (MIC/MBC): for GISA-992, 0.5/1.0 and 16/16; for VREF-590, 2.0/2.0 and 32/32; and for MRSA-494, 0.25/0.25 and 1.0/4.0 microg/ml, respectively. During the first 8 h daptomycin significantly reduced the inoculum for all organisms. Daptomycin at 6 mg/kg/day and 10 mg/kg/day had log(10) CFU/g reductions of 5 and 6, 3.4 and 5, and 6.4 and 6.5 by 8 h for GISA-992, VREF-590, and MRSA-494, respectively. Against both GISA-992 and VREF-590, the D10 regimen achieved the limit of detection at 72 h, with D6 regimens showing slight regrowth. A concentration-dependent killing effect was noted to occur, with daptomycin demonstrating a more rapid and greater kill from the D10 versus the D6 regimen. The results of this study suggest that daptomycin demonstrates significant (P < 0.05) activity against gram-positive organisms in a simulated sequestered infection site.


Subject(s)
Anti-Bacterial Agents/pharmacology , Daptomycin/pharmacology , Endocarditis, Bacterial/microbiology , Enterococcus faecium/drug effects , Methicillin Resistance/genetics , Staphylococcus aureus/drug effects , Staphylococcus aureus/genetics , Vancomycin/pharmacology , Anti-Bacterial Agents/pharmacokinetics , Daptomycin/pharmacokinetics , Drug Resistance, Microbial , Enterococcus faecium/growth & development , Half-Life , Microbial Sensitivity Tests , Models, Biological , Staphylococcus aureus/growth & development , Vancomycin/pharmacokinetics , Vancomycin Resistance
14.
Antimicrob Agents Chemother ; 44(7): 1925-9, 2000 Jul.
Article in English | MEDLINE | ID: mdl-10858356

ABSTRACT

Daptomycin, a lipopeptide antibiotic, has broad activity against gram-positive organisms, similar to vancomycin; however, its mechanism of action differs, resulting in interference with cell membrane transport and a more rapid bactericidal activity. In light of increasing need for alternative treatments against intermediate-resistant Staphylococcus aureus, there is revitalized interest in this antibiotic. We, therefore, evaluated the activity of daptomycin alone or in combination in an in vitro infection model against two glycopeptide intermediate-resistant S. aureus (GISA) isolates. Newly designed regimens of daptomycin at 4 and 6 mg/kg of body weight every 24 h (q24h) were compared to the previous regimen of 3 mg/kg q12h. Daptomycin MICs and minimal bactericidal concentrations (MBCs) (MIC/MBC) for Mu-50, HIP5836 (992), and MRSA-67 were 0.5/1.0, 0.5/1.0, and 0.125/0.5 microgram/ml, respectively. MICs and MBCs of arbekacin for the three strains were 2.0/8.0, 0. 125/0.5, and 0.125/0.25 microgram/ml, respectively. Vancomycin and gentamicin MICs and MBCs for the three strains were 8.0/8.0, 8.0/8.0, and 0.5/1.0 microgram/ml and 128/128, 0.5/1.0, and 0.25/0.5 microgram/ml, respectively. Our experience with daptomycin in an in vitro infection model has shown significant kill against the two GISA strains (Mu-50 and 992) (P < 0.03). We also noted that kill was related to a total dose effect for 992, in which simulated daptomycin in vivo dosages of 6 mg/kg q24h and 3 mg/kg q12h produced similar kill and 4 mg/kg q24h resulted in significant regrowth (P

Subject(s)
Aminoglycosides , Drug Therapy, Combination/pharmacology , Microbial Sensitivity Tests/methods , Staphylococcal Infections/drug therapy , Staphylococcus aureus/drug effects , Anti-Bacterial Agents/pharmacokinetics , Anti-Bacterial Agents/pharmacology , Daptomycin/pharmacokinetics , Daptomycin/pharmacology , Dibekacin/analogs & derivatives , Dibekacin/pharmacokinetics , Dibekacin/pharmacology , Drug Resistance, Microbial/physiology , Drug Therapy, Combination/pharmacokinetics , Gentamicins/pharmacokinetics , Gentamicins/pharmacology , Humans , Models, Biological , Staphylococcal Infections/metabolism , Staphylococcal Infections/microbiology , Staphylococcus aureus/metabolism , Vancomycin/pharmacokinetics , Vancomycin/pharmacology
15.
J Pediatr ; 136(6): 844-6, 2000 Jun.
Article in English | MEDLINE | ID: mdl-10839889

ABSTRACT

A boy with failure to thrive and isolated pancreatic amylase deficiency is described. Immunoprecipitation confirmed only salivary isoamylase in duodenal fluid at ages 20 and 33 months. Because normal pancreatic amylase messenger RNA was detected by reverse-transcriptase polymerase chain reaction in the fluid, failure of the normal maturation of pancreatic amylase secretion may explain the deficiency.


Subject(s)
Amylases/deficiency , Failure to Thrive/etiology , Pancreas/enzymology , Failure to Thrive/enzymology , Humans , Infant , Male
16.
J Infect Dis ; 181(3): 1198-201, 2000 Mar.
Article in English | MEDLINE | ID: mdl-10720555

ABSTRACT

Candida endophthalmitis is a serious infection secondary to hematogenous dissemination or direct inoculation of the organisms following trauma or eye surgery. The diagnosis is based on the characteristic findings in the infected eye and on culture of vitreous samples. Unfortunately, the yield of vitreous cultures is limited. The use of a Candida albicans species-specific polymerase chain reaction (PCR) assay in the diagnosis of Candida endophthalmitis is reported herein. Four patients with suspected fungal endophthalmitis underwent vitrectomy for diagnostic and therapeutic purposes. In 2 of the 4, vitreous cultures were negative. However, characteristic PCR products were generated in all 4 patient specimens, enabling the rapid diagnosis of Candida endophthalmitis in all 4. Clinical response was observed in all cases. These results demonstrate the utility of PCR-mediated detection of C. albicans in vitreous samples.


Subject(s)
Aqueous Humor/microbiology , Candida albicans/isolation & purification , Candidiasis/diagnosis , DNA, Fungal/analysis , Endophthalmitis/diagnosis , Polymerase Chain Reaction/methods , Adult , Aged , Candida albicans/genetics , Humans , Male , Middle Aged , Species Specificity
17.
Rev Iberoam Micol ; 17(2): 60-3, 2000 Jun.
Article in English | MEDLINE | ID: mdl-15813697

ABSTRACT

Candida species are an important cause of opportunistic infection in the oral cavity of immunocompromised patients, especially HIV infected patients. Melaleuca oil obtained commercially was investigated since it is known to have broad antifungal properties. The in-vitro susceptibilities of Aspergillus and susceptible and resistant Candida species were performed utilizing serial dilutions in microtiter plates with Sabouraud dextrose agar and the commercial preparation of Melaleuca. As a comparator, in vitro susceptibilities to amphotericin B and fluconazole were also determined using the broth microdilution technique. The results demonstrate that Melaleuca inhibited the Candida species. However, the growth of Aspergillus was not inhibited at the concentrations tested. Thus, preparations containing Melaleuca alternafolia may be a useful alternative for superficial candidal infections. In fact, it may be a useful alternative regimen for advanced HIV-positive patients with oropharyngeal candidiasis refractory to fluconazole. However, controlled clinical studies to evaluate its efficacy are still needed.

18.
Pharmacotherapy ; 19(11): 1315-20, 1999 Nov.
Article in English | MEDLINE | ID: mdl-10555937

ABSTRACT

A retrospective evaluation was conducted to determine which children admitted for fever and neutropenia required empiric vancomycin therapy, and to develop a clinical pathway for appropriate treatment. Chart review identified 109 admissions of 36 pediatric oncology patients for fever and neutropenia, of which 88 were eligible for analysis. Blood cultures isolated 17 gram-positive organisms; coagulase-negative staphylococci and viridans group streptococci were cultured most frequently (82%). We concluded that previous high-dose cytarabine therapy, inflamed central access site, and hypotension or septic shock are possible indicators of febrile, neutropenic patients at high risk for gram-positive pathogen isolation. These predictors then were used to determine which children would receive empiric vancomycin therapy.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Bacterial Infections/drug therapy , Fever/drug therapy , Neutropenia/drug therapy , Vancomycin/therapeutic use , Adolescent , Child , Child, Preschool , Cytarabine/therapeutic use , Female , Humans , Infant , Male , Retrospective Studies
19.
Tissue Eng ; 5(2): 103-18, 1999 Apr.
Article in English | MEDLINE | ID: mdl-10358218

ABSTRACT

The mammalian heart does not regenerate in vivo. The heart is, therefore, an excellent candidate for tissue engineering approaches and for the use of biosynthetic devices in the replacement or augmentation of defective tissue. Unfortunately, little is known about the capacity of isolated heart cells to re-establish tissue architectures in vitro. In this study, we examined the possibility that cardiac cells possess a latent organizational potential that is unrealized within the mechanically active tissue but that can be accessed in quiescent environments in culture. In the series of experiments presented here, total cell populations were isolated from neonatal rat ventricles and recombined in rotating bioreactors containing a serum-free medium and surfaces for cell attachment. The extent to which tissue-like structure and contractile function were established was assessed using a combination of morphological, physiological, and biochemical techniques. We found that mixed populations of ventricular cells formed extensive three-dimensional aggregates that were spontaneously and rhythmically contractile and that large aggregates of structurally-organized cells contracted in unison. The cells were differentially distributed in these aggregates and formed architectures that were indistinguishable from those of intact tissue. These architectures arose in the absence of three-dimensional cues from the matrix, and the formation of organotypic structures was apparently driven by the cells themselves. Our observations suggest that cardiac cells possess an innate capacity to re-establish complex, three-dimensional, cardiac organization in vitro. Understanding the basis of this capacity, and harnessing the organizational potential of heart cells, will be critical in the development of tissue homologues for use in basic research and in the engineering of biosynthetic implants for the treatment of cardiac disease.


Subject(s)
Heart, Artificial , Myocardium/cytology , Actins/analysis , Animals , Animals, Newborn , Biomedical Engineering/methods , Bioreactors , Cell Adhesion , Culture Media, Serum-Free , Embryonic and Fetal Development , Fibronectins , Heart Ventricles , Microscopy, Electron , Microscopy, Electron, Scanning , Myocardium/ultrastructure , Myosin Heavy Chains/analysis , Rats , Rats, Sprague-Dawley
20.
Antimicrob Agents Chemother ; 43(4): 836-45, 1999 Apr.
Article in English | MEDLINE | ID: mdl-10103188

ABSTRACT

Recent studies have revealed an increase in the incidence of serious infections caused by non-albicans Candida species. Candida lusitaniae is of special interest because of its sporadic resistance to amphotericin B (AmB). The present in vitro study demonstrated that, unlike other Candida species, C. lusitaniae isolates frequently generated AmB-resistant lineages form previously susceptible colonies. Cells switching from a resistant colony to a susceptible phenotype were also detected after treatment with either UV light, heat shock, or exposure to whole blood, all of which increased the frequency of switching. In some C. lusitaniae lineages, after a cell switched to a resistant phenotype, the resistant phenotype was stable; in other lineages, colonies were composed primarily of AmB-susceptible cells. Although resistant and susceptible lineages were identical in many aspects, their cellular morphologies were dramatically different. Switching mechanisms that involve exposure to antifungals may have an impact on antifungal therapeutic strategies as well as on standardized susceptibility testing of clinical yeast specimens.


Subject(s)
Amphotericin B/pharmacology , Antifungal Agents/pharmacology , Candida/drug effects , Candidiasis/microbiology , Drug Resistance, Microbial/physiology , Blood , Candida/physiology , Candida/radiation effects , Heat-Shock Response , Humans , Phenotype , Ultraviolet Rays
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